A falling Australian dollar and cheaper oil might be providing a ray of sunshine for Australian coal producers, but these improved conditions are helping to prevent the very thing the broader sector needs – mine closures.

BHP Billiton appears to be pressing ahead to prepare to bid for lucrative offshore oil fields being auctioned by Mexico, despite the plunge in the crude oil price and plans to cut its onshore drilling in the neighbouring US.

Anyone expecting the collapse in oil prices to bring them relief on their gas and power bills can think again For households and most of industry, the benefits of the plummeting crude oil price will be strictly limited to their petrol and diesel expenses.

Brent has risen for the first time in six days amid speculation about the price level that will force some producers to curb investment and limit future supply growth. West Texas Intermediate advanced in New York.

Global oil prices have extended their falls this week, but consumers have not seen any change in petrol prices at the pump. Instead, national petrol prices headed higher, according to the numbers produced by the Australian Institute of Petroleum.

Updated | Australian energy stocks are set to be “annihilated” on Friday after Brent oil sunk to a four-year low overnight, with Origin and Santos tipped to fare the worst, according to an oil and gas expert.

A new age of abundant and cheap energy supplies is redrawing the world's geopolitical landscape, weakening and potentially threatening the legitimacy of some governments while enhancing the power of others.

Russia’s economy will sink into a recession next year if the price of oil slumps to $US60 a barrel and the US and its allies tighten sanctions over the conflict in Ukraine, says Finance Minister Anton Siluanov.